<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    .box{
        width: 150px;height: 150px;
        position: relative;
        overflow: hidden;
        background-color: pink;
    }
    .cover{
        width: 0;height: 0;
        /* background-color: orangered; */
        background: rgba(255, 69, 0, 0.6);
        position: absolute;
        transition: all 1s;
        transform: rotate(180deg);
        transform-origin: 50% 50%;
    }
    .box:hover .cover{
        width: 150px;height: 150px;
        transform: rotate(0deg);
    }
    </style>
</head>
<body>
    <div class="box">
        <div class="cover"></div>
    </div>
</body>
</html>